The problem of film cameras creating double exposures is a familiar one. After reinserting partially exposed film back into a camera. There is a need for a simple, reliable and inexpensive way of preventing a camera from creating double exposures, particularly when the film is reloaded after prior exposures have caused the film to be wound to near mid-roll.
Magnetically recording data on film by the film manufacturer, the camera, the customer order station and the photofinisher is described in the above-referenced patent application by Cloutier et al. Typically, using the ability to magnetically record data on the film to provide mid-roll interrupt protection (i.e., to prevent the camera from double exposing the film) has required the camera to be able to interpret the recorded data. The disadvantage is that interpreting the data is an elaborate task, as described in the above-referenced Cloutier application. As such, a mid-roll interrupt protection system in a camera which reads and interprets the magnetically recorded data must be disadvantageously elaborate. Moreover, it is not possible to provide such a system in those cameras not having the ability to read and interpret magnetically recorded data.
Accordingly, it is the object of the present invention to provide a mid-roll interrupt protection system in a camera which is simple and inexpensive and does not require that the camera to read, decode or interpret data magnetically recorded on the film in order to prevent double exposures.